Bugga bugga chugga bugga cruise

-
Namehtnad

Namehtnad

Well-Known Member
Joined
Mar 6, 2017
Messages
82
Reaction score
22
Location
Daygo
Hello folks, back for more help. Installed a new 1406 edlebrock on my car and was running like a dream, 67 valiant commando 273, but I've been noticing a slight miss while cruising, no idle issues, idles like a dream. At wot (when not warmed up will definitely lean out and go POP!) When warmed up no issues. Hammer down and go. But no matter warm or cold, misses while cruising. When cold a slight bogg whilst accelerating. When warm no acceleration issue. Only whilst cruising... Any advice helps
 
The 1406 has a reputation for doing that if it;s on anything other than a stock or mostly stock engine. It is the economy version. The 1405 is the performance version. The 1406 is jetted VERY lean. Just because it;s a 600, doesn't necessarily mean it's "big enough" for even a 273. It's all in the jetting. Also, you cannot turn a 1406 into a 1405.
 
Wouldn't like to. Maybe I shoulda gotten the 1405...It was 30$ cheaper, but I thought, eh I don't wanna mess with changing electric choke AFB to manual edlebrock
 
I was running and 1806 and I thought it ran too lean. I had to keep messing with different jet and rod combinations but still I wasn't happy. It ended up OK on cruise, but lean on power - too lean.

The popping could be due to it leaning out. Probably need to richen it up with different rods (thinner rods are richer rods) or combination of jet and rods.
 
Would bigger jets help with the cruise bugga bugga chugga? It does seem like it's using way too much fuel.
 
Another question, why doesn't it seem to lean out when givin 'er hell when all warmed up as opposed to cold?
 
By the way the 1406 comes with the following jets and rods:

Metering Jets - Primary .098, Secondary .095; Metering Rods - .075 x .047
 
JoesEdge said:
By the way the 1406 comes with the following jets and rods:

Metering Jets - Primary .098, Secondary .095; Metering Rods - .075 x .047
Click to expand...
I'm not gonna lie, I have no idea what any of that **** means. Just was never a carb man
 
I think the best course of action would be to take it to a feller who knows how to tune and re-jet a carb. And I think I'll check my timing to. Maybe I'll drive home with my vac advance plugged up and see where that leads me. I did notice no change in timing when I had it at partial throttle and removed the vac advance hose from the distributor. (I'm a tall guy)
 
Would Messing with the mixture screws do anything to help, or is that just purely a jetting issue?
 
JoesEdge said:
The mixture screws only either adds or removes fuel from the idle.
Click to expand...
Awesome thank you, guess that's why idle is cherry. I spent 2 hrs making sure it was idling right. I kept fiddling with it until it got worse then put it back the way I had it when it was the best
 
This was 9 in the morning on a Sunday. My neighbor was pissed, moreso because I kept revving it to see where idle dropped to, then adjust...Wait, rev.... Adjust...You get the picture
 
As for my next question, where would I acquire said jets and rods, and is the any way to adjust the jets currently on the carb, or do the sit in a set position?
 
The easiest way to get a richer mixture at cruise in your case is to change the rods to .073 x .047 (Edelbrock 1456)
The 1406 is a really good carb once you got it tuned right.
There IS a difference between 1405 and 1406 but not THAT much, I've got both of them and I can tune the 1406 to run just as good as the 1405 on my 383HP
I use a wideband O2 sensor when I tune and that helps alot.
 
Okie doke, just watched an instructional video on how to re-jet. (YouTube) Wow so simpuhl!!! I can't believe I have rebuilt aircraft, big truck, motorcycle, minibike, goped, lawnmower, and car engines (14 stage axial flow for the aircraft) yet was afraid to dig into a carb till I saw the video. (I guess the thought of losing that little spring on the rod fùcked my world up or that little seat ball whatever the f that does) now to just source some jets and rods
 
Mine did this once. It had a burnt plug wire that would only touch the header at highway speeds.
 
73Swinger18 said:
Now you're talking my language. Are you a Mech? Sounds like the T56.
Click to expand...
Yessir...The general electric t56-15, t56-a7, aaaaand the brand new rolls Royce ae2100d3 in the newest flying pigs...Well was engines, now I'm a machine operator at a shipyard
 
Sedanman said:
Let's see some pics of that Valiant. Is it a factory commando?
Click to expand...
Checkem my other thread.....Plenty of them pictures, and yep factory 4 door commando. Code e on vin.... Numbers matching...cept the Eddy, I do have the original AFB that's just fubar.
 
Namehtnad said:
Another question, why doesn't it seem to lean out when givin 'er hell when all warmed up as opposed to cold?
Click to expand...

carb's run lean when they are cold. that's why you're supposed to do your tuning (idle mix) when the motor is all the way up to operating temp.
 
You must log in or register to reply here.
-

Back
Top